Rap music with high levels of bass played at an absurdly high volume. It usually derives from a mid-1990's Cadillac with a poor quality sound system that can be heard rattling hundreds of feet away. It can also originate from a home, most of the time occurring at an unreasonable hour in the early A.M.

I was indulging in some Van Halen on my way to work when a Cadillac Seville pulls up next to me and drowns out the guitar solo from "Panama" with some deafening Nig Noise.